JP4335413B2 - Assembly method of motor rotating shaft - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of assembling a motor rotating shaft in which a thrust load of a motor rotating shaft having one end inserted into the shaft hole is supported by a resin filled and solidified in a shaft hole provided in the motor housing.
[0002]
[Prior art]
The rotor (armature) of the motor is accommodated in the housing, and the rotation shaft (armature shaft) is rotatably supported by the housing. In this case, as a method of assembling the rotating shaft that supports the thrust load of the rotating shaft by a simple method, a rubber cushion is disposed at the tip of the rotating shaft, and the rubber cushion is assembled while being pressed by the rotating shaft. A method of supporting a thrust load of a rotating shaft by a rubber cushion elastic force is known. This type of assembly method is easy to assemble, but on the other hand, there is a problem that a reverse noise is generated when the motor is reversed because thrust backlash is generated along with the elastic deformation of the rubber cushion.
[0003]
Therefore, as a method of assembling the rotating shaft that prevents the occurrence of thrust play and supports the thrust load, a method of filling the tip of the rotating shaft with a resin such as polyacetal and curing the resin to support the rotating shaft is known. ing. With this type of assembly method, variations in the dimensional accuracy of individual parts can be absorbed, and the rotating shaft can be supported in a state corresponding to the thrust force of the rotating shaft by a simple method.
[0004]
However, in such a conventional assembling method, since the resin is filled into the tip of the rotating shaft after the assembling of the rotating shaft to the motor body, an injection molding machine for filling the resin is necessary and the equipment cost is reduced. However, there is a problem that the number of work steps is increased.
[0005]
Further, in such a conventional assembling method, since a thermoplastic resin is used as the resin to be filled in the tip end portion of the rotating shaft, there is a possibility that the resin melts due to heat generated by the thrust load support portion. For this reason, it is necessary to arrange a heat insulating plate between the rotating shaft and the resin, and there is a problem that the number of parts increases and the number of work steps further increases. Further, even with such a heat insulating plate, it is impossible to prevent the resin from being melted out, and there is a possibility that the state where the thrust load of the rotating shaft is supported cannot be maintained. That is, the occurrence of thrust backlash may not be prevented.
[0006]
[Problems to be solved by the invention]
In view of the above facts, an object of the present invention is to provide a method for assembling a motor rotating shaft that requires less man-hours when assembling the rotating shaft, is easy to work, has low equipment costs, and does not generate thrust backlash.
[0007]
[Means for Solving the Problems]
In the motor rotating shaft assembling method according to the first aspect of the present invention, one end of the motor rotating shaft connected to the rotor and provided with the rotation transmitting portion is located in a shaft hole provided in the motor housing. In the method of assembling the motor rotating shaft in which the thrust load of the motor rotating shaft is supported by the resin filled and solidified in the shaft hole, the resin material is a heat resistant resin, and the heat resistant resin can be plastically deformed. In the state where the heat-resistant resin is placed on the tip of the motor rotation shaft, the motor rotation shaft is inserted into the shaft hole and the heat-resistant resin is pressed by the motor rotation shaft. It is characterized by filling.
[0008]
In the method of assembling the motor rotating shaft according to the first aspect, when the motor is assembled, the heat-resistant resin in a plastically deformable state is inserted into the shaft hole provided in the motor housing before the motor rotating shaft. That is, for example, a state in which the leading end to the heat-resistant resin of the motor rotation shaft is pre-mounted.
[0009]
In this state, while inserting the motor rotation shaft into the shaft hole, the motor rotation shaft is pressed with the heat resistant resin to fill the shaft hole. The heat resistant resin is solidified (cured) at a predetermined temperature in the shaft hole.
[0010]
As a result, the motor rotating shaft directly or indirectly contacts the cured heat-resistant resin and is supported in a state corresponding to the thrust load.
[0011]
As described above, since the heat-resistant resin is filled into the shaft hole while the motor rotating shaft is inserted into the shaft hole, a support structure for the thrust load can be easily obtained when the motor rotating shaft is assembled, and the motor rotating shaft is assembled. The work after attachment becomes unnecessary. In addition, an injection molding machine for filling the shaft hole with the heat resistant resin is also unnecessary.
[0012]
Furthermore, since the motor rotating shaft is supported using the heat resistant resin, there is no fear that the resin melts with the heat generation of the support portion, and the state where the thrust load is supported is maintained. Further, a heat insulating plate between the motor rotating shaft and the heat resistant resin is not required, the number of parts is reduced, and the number of assembling steps is further reduced.
[0013]
As described above, in the method for assembling the motor rotating shaft according to the first aspect, the number of work steps when assembling the rotating shaft is small, the operation is easy, the equipment cost is low, and the thrust play does not occur.
[0014]
A motor rotating shaft assembling method according to a second aspect of the present invention is the motor rotating shaft assembling method according to the first aspect , wherein the heat resistant resin is placed on the tip of the motor rotating shaft via an intermediate member. In this state, the motor rotating shaft is inserted into the shaft hole.
[0015]
3. The motor rotating shaft assembling method according to claim 2, wherein when the motor is assembled, the motor rotating shaft is inserted into the shaft hole in a state where a heat resistant resin is placed on the tip of the motor rotating shaft via an intermediate member. Then, the heat-resistant resin is pressed by the motor rotation shaft through this intermediate member to fill the shaft hole.
[0016]
For this reason, for example, by forming the intermediate member in a shape suitable for the placement of the heat resistant resin, a careful work for preventing the heat resistant resin from falling off is not required, and the heat resistance is easily achieved. The resin can be inserted into the shaft hole. Further, for example, if the intermediate member has a dimension and shape corresponding to the shaft hole, the heat resistant resin can be prevented from leaking to the motor rotating shaft side when the heat resistant resin is pressed and filled in the shaft hole. Careful work to prevent this is not required, and the heat-resistant resin can be easily filled into the shaft hole.
[0017]
As described above, in the method for assembling the motor rotating shaft according to claim 2, the number of work steps for assembling the rotating shaft is small, the operation is further facilitated, the equipment cost is low, and thrust play does not occur.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to FIGS.
[0019]
FIG. 1 is a front view in which a geared motor 10 to which a motor rotating shaft assembling method according to an embodiment of the present invention is applied is partially broken. Moreover, the bearing part 22 of the geared motor 10 is shown by the plane sectional view and the side sectional view in FIG.
[0020]
The geared motor 10 includes a motor unit 10A and a gear unit 10B connected to the motor unit 10A. One end of the armature shaft 16 of the armature 14 is supported in the yoke 12 of the motor unit 10A by a bearing unit (not shown).
[0021]
The distal end portion of the armature shaft 16 extends into the motor housing 18 of the gear portion 10B connected to the yoke 12.
[0022]
On the other hand, in the gear portion 10B, a worm gear 20 as a motor rotation shaft is connected to the armature shaft 16, and a tip portion 20A of the worm gear 20 is supported on the motor housing 18 by a bearing portion 22. The motor housing 18 has a substantially cup shape that houses the worm gear 20 and the wheel gear 24 that meshes with the worm gear 20, and the cup-shaped opening is closed by a cover 26. Further, a driven system such as a power window regulator or a sunroof is connected to the output shaft of the wheel gear 24.
[0023]
As shown in detail in FIG. 2, the motor housing 18 is provided with a shaft hole 28 in the bearing portion 22 that supports the tip portion 20 </ b> A of the worm gear 20. The shaft hole 28 is opened along the axis of the worm gear 20 with the inside of the motor housing being opened, and has a large-diameter portion 28A and a hexagonal cross-sectional portion 28B having a circular cross section. Further, the hexagonal cross section 28 </ b> B communicates with a communication hole 28 </ b> C that has an axis perpendicular to the axis and opens on the cup-shaped opening side (upper side in FIG. 2B) of the motor housing 18.
[0024]
In the bearing portion 22, a radial bearing 30 is disposed in the large-diameter portion 28 </ b> A of the shaft hole 28, and the distal end portion 20 </ b> A of the worm gear 20 is inserted into the radial bearing 30 so that the radial load of the worm gear 20 is supported. It has become.
[0025]
Further, the metal plate 32 comes into contact with the tip portion 20 </ b> A of the worm gear 20. The metal plate 32 is formed in a substantially hexagonal cross section so that it can be inserted into the hexagonal cross section 28B, and a recess in which the heat resistant resin 34 can be placed is formed at one end thereof.
[0026]
Thereby, in the bearing portion 22, in the assembled state of the geared motor 10, the metal plate 32 is inserted into the hexagonal cross section 28B of the shaft hole 28, and this metal plate 32 is inserted into the hexagonal cross section 28B and the communication hole 28C of the shaft hole 28. The heat-resistant resin 34 filled and hardened is held in contact with the tip 20A of the worm gear 20 to support the thrust load of the worm gear 20.
[0027]
The heat-resistant resin 34 is in a plastically deformable state (clay-like) in a cooled state, and is a room-temperature curable resin that cures when left at room temperature, or is in a state that can be plastically deformed at room temperature. A thermosetting resin that cures when heat is applied can be used.
[0028]
Next, the operation of the present embodiment will be described with reference to FIGS.
[0029]
In the geared motor 10 having the above configuration, when the thrust adjustment of the worm gear 20 (assembly of the geared motor 10) is performed, the armature 14 integrated with the armature shaft 16 to which the worm gear 20 is connected is disposed in the yoke 12 as shown in FIG. Assemble to. On the other hand, a radial bearing 30 or the like is assembled to the motor housing 18.
[0030]
Next, as shown in FIGS. 4A and 4B, an appropriate amount (clay-like) heat-resistant resin 34 in a plastically deformable state is formed into a cylindrical shape that can be inserted into the shaft hole 28. The cylindrical heat-resistant resin 34 is placed in the concave portion of the metal plate 32, and the metal plate 32 with the heat-resistant resin 34 placed thereon is placed on the tip 20 </ b> A of the worm gear 20. In this state, the worm gear 20 is inserted into the motor housing 18 until the end surface 12A of the yoke 12 and the end surface 18A of the motor housing 18 come into contact with each other. As a result, the heat resistant resin 34 is inserted into the shaft hole 28 prior to the distal end portion 20 </ b> A of the worm gear 20.
[0031]
When the worm gear 20 is inserted into the motor housing 18, the heat-resistant resin 34 passes through the radial bearing 30 provided in the large-diameter portion 28A of the shaft hole 28 (the state shown in FIGS. 4C and 4D). Then, it comes into contact with the end of the hexagonal cross section 28B of the shaft hole 28 (state of FIGS. 4E and 4F). When the worm gear 20 is further inserted into the motor housing 18 from this state, the heat-resistant resin 34 is pressed by the tip portion 20A (metal plate 32) of the worm gear 20 and within the hexagonal section 28B of the shaft hole 28. Deformation begins to fill.
[0032]
When the end surface 12A of the yoke 12 and the end surface 18A of the motor housing 18 come into contact with each other, the insertion of the worm gear 20 into the motor housing 18 (the pressing of the heat resistant resin 34 by the tip portion 20A of the worm gear 20) is finished. At this time, the metal plate 32 is inserted into the hexagonal cross section 28 </ b> B and the tip 20 </ b> A of the worm gear 20 is inserted into the radial bearing 30. On the other hand, the heat-resistant resin 34 is filled in the hexagonal cross section 28B, and a part thereof protrudes from the opening of the communication hole 28C (states of FIGS. 4G and 4H).
[0033]
The heat resistant resin 34 protruding from the communication hole 28 </ b> C is cut, and the yoke 12 and the motor housing 18 are fixed with the fixing screw 27.
[0034]
Here, when a room temperature curable resin that cures at room temperature is used as the heat resistant resin 34, the heat resistant resin 34 is heated at a temperature lower than room temperature so that the heat resistant resin 34 can be plastically deformed during assembly. A forming operation into a cylindrical shape, an inserting operation of the worm gear 20 into the motor housing 18 and the like are performed, and then left at room temperature to cure the heat resistant resin 34. On the other hand, when a thermosetting resin is used as the heat resistant resin 34, the heat resistant resin 34 is formed into a cylindrical shape at room temperature (room temperature), the worm gear 20 is inserted into the motor housing 18, and the like. Then, the vicinity of the bearing portion 22 filled with the heat resistant resin 34 is heated from the outside of the motor housing 18 to cure the heat resistant resin 34.
[0035]
Further, after the heat resistant resin 34 is cured, the wheel gear 24 is assembled in the motor housing 18, and the opening of the motor housing 18 is closed by the cover 26.
[0036]
Thus, the geared motor 10 is assembled to press the heat-resistant resin 34 placed on the worm gear 20 while the worm gear 20 is inserted into the shaft hole 28 to fill the hexagonal section 28B of the shaft hole 28. At this time, the thrust adjustment is easily performed and the work after the assembly becomes unnecessary. Further, an injection molding machine for filling the heat-resistant resin 34 into the hexagonal cross section 28B becomes unnecessary.
[0037]
Furthermore, since the worm gear 20 is supported using the heat-resistant resin 34, there is no fear that the resin will melt with the heat generation of the support portion, and the state in which the thrust is adjusted is maintained. As a result, a heat insulating plate between the tip 20A (metal plate 32) of the worm gear 20 and the heat-resistant resin 34 becomes unnecessary, the number of parts is reduced, and the number of assembling steps is further reduced.
[0038]
Furthermore, since the heat resistant resin 34 indirectly contacts the rotating shaft via the metal plate 32, wear of the heat resistant resin 34 due to rotation on the rotating shaft is prevented. Further, since the metal plate 32 has a substantially hexagonal cross section and is inserted into the hexagonal cross section 28B, the metal plate 32 is also prevented from being rotated along with the rotation of the worm gear 20. Further, the metal plate 32 prevents the heat resistant resin 34 from leaking into the gap between the tip 20A of the worm gear 20 and the shaft hole 28, and requires careful work so that the heat resistant resin 34 does not leak. The thrust adjustment (assembly of the geared motor 10) is further facilitated.
[0039]
In addition, the shape of the heat resistant resin before being pressed and filled is not limited to a cylindrical shape, and may be an arbitrary shape such as a rectangular parallelepiped, a triangular pyramid, or an indefinite shape. Furthermore, in this Embodiment, it applied using the heat resistant resin 34, However, This invention is not limited to this, For example, it can replace with a heat resistant resin and can also apply using a thermoplastic resin etc. In this case, it is desirable to provide a heat insulating plate between the tip portion 20A of the worm gear 20 and the thermoplastic resin or the like.
[0040]
In the present embodiment, the heat-resistant resin 34 is placed on the tip 20A of the worm gear 20 via the metal plate 32. However, the present invention is not limited to this, and the metal plate 32 is not used. The heat resistant resin 34 may be directly placed on the tip 20A of the worm gear 20, or the heat resistant resin 34 may be placed on the tip 20A of the worm gear 20 via another member.
[0041]
Further, the metal plate 32 has a hexagonal cross section, and this is inserted into the hexagonal cross section 28B of the shaft hole 28 to prevent the accompanying rotation. However, the present invention is not limited to this, for example, the metal plate A recess may be formed at a position eccentric from the center, and the resin inserted into the recess may be cured to prevent follow-up.
[0042]
Furthermore, in the present embodiment, a communication hole 28C is provided in a direction perpendicular to the shaft hole 28, and excess heat-resistant resin 34 is discharged from the communication hole 28C. However, the present invention is not limited to this. For example, the communication hole may be provided in the axial direction of the shaft hole, or the heat-resistant resin may not be discharged without providing the communication hole by controlling the amount of heat-resistant resin used.
[0043]
As described above, in the method of assembling the rotating shaft applied to the geared motor 10 according to the present embodiment, the thrust adjustment is easily performed when the geared motor 10 is assembled, and the work after the assembly is unnecessary. There are few man-hours, no injection molding machine is required, the equipment cost is low, and there is no thrust play due to resin melting.
[Brief description of the drawings]
FIG. 1 is a partially broken front view of a geared motor to which a motor rotating shaft assembling method according to an embodiment of the present invention is applied.
FIG. 2A is a front sectional view showing a configuration of a bearing portion of a geared motor to which a motor rotating shaft assembling method according to an embodiment of the present invention is applied, and FIG. 2B is a side sectional view. is there.
FIG. 3 is a partially broken front view showing a state before the assembly of the geared motor to which the motor rotating shaft assembling method according to the embodiment of the present invention is applied.
FIG. 4 is a diagram showing an assembly process of a geared motor to which a motor rotating shaft assembling method according to an embodiment of the present invention is applied, and FIG. 4 (A) shows a state where a resin is placed in a worm gear shape. (B) is a plan view, (C) is a front view when the worm gear is inserted into the shaft hole, (D) is the plan view, and (E) is a resin abutting against the wall surface of the shaft hole. The front view which shows a state, (F) is the same top view, (G) is the front view which shows the state with which resin was filled in the axial hole, (H) is the same top view.
[Explanation of symbols]
10 geared motor 18 motor housing 20 worm gear (motor rotating shaft)
22 Bearing part 28 Shaft hole 32 Metal plate (intermediate member)
34 Heat-resistant resin (resin)

Claims (2)

One end portion of a motor rotating shaft connected to the rotor and provided with a rotation transmitting portion is located in a shaft hole provided in the motor housing, and the motor rotating shaft is filled with resin solidified in the shaft hole. In the method of assembling the motor rotating shaft that supports the thrust load of
The resin material is a heat resistant resin,
While the heat resistant resin is in a plastically deformable state and the heat resistant resin is placed on the tip of the motor rotating shaft, the motor rotating shaft is inserted into the shaft hole and the heat resistant resin is inserted into the shaft rotating hole. Press the resin to fill the shaft hole,
A method for assembling a motor rotating shaft. The motor rotating shaft assembly according to claim 1 , wherein the motor rotating shaft is inserted into the shaft hole in a state where the heat resistant resin is placed on an end of the motor rotating shaft via an intermediate member . Method.

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